Recently, social networking services (SNS), for example, online chat rooms, internet forums and bulletin boards, instant messaging and the like, have become increasingly prevalent. Social networking services such as these enable people having similar interests, for example, sports, music, babies, politics and the like, to rendezvous in virtual communities. Typical, a user creates the virtual community, for example, an online chat room or bulletin board, and defines its context, for example, rock music. Virtual communities may also be set tip to discuss ongoing events, for example, concerts, television, shows, sporting events and the like. In particular, a user can set up an online chat room to discuss an ongoing football game, or create an online forum where people can comment on a beauty contest currently being shown on television. Thus, the emergence of virtual communities may allow users to communicate with others having like interests without leaving the comfort of their home or office.